In one known form of adjustable floating reamer as disclosed, for example, in the M. L. Benjamin et al U.S. Pat. No. 3,728,037, the lost in the shank member is closed by a closure cap in the form of a plate which is secured by screws to the end of the shank member and hence the shank member and cap must be of relatively large diameter to provide a wall thickness of metal around the threaded holes in the shank member and around the screw head counterbores in the cap.
Although the adjustable floating reamer of said U.S. Pat. No. 3,728,037 contemplates radial floating movement of the blades such movement is about relatively closely spaced-apart parallel pivots perpendicular to the blade slot.